We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byJameson Munson
Modified over 2 years ago
Copyright © 2014 Delmar, Cengage Learning Environmental and Safety Practices Instructor Name: (Your Name) 2 CHAPTER
Copyright © 2014 Delmar, Cengage Learning Learning Objectives Describe the effects of CFCs on the worlds ozone layer. Explain the Clean Air Act. Identify the pros and cons of CFCs, HCFCs, and HFCs. Work safely with mobile air-conditioning and refrigeration equipment.
Copyright © 2014 Delmar, Cengage Learning Learning Objectives (continued) Explain the differences between virgin, recycled, and recovered refrigerant. Explain the greenhouse effect and its impact on our environment. List the greenhouse gases. Explain the differences between disposable and refillable refrigeration containers.
Copyright © 2014 Delmar, Cengage Learning Learning Objectives (continued) Discuss the rationale for alternate refrigerants. Understand the health hazards of working with refrigerants. Explain how refrigerants may produce poisonous gases. Learn to how handle refrigerant containers safely. Understand general workplace precautions for working with refrigerants.
Copyright © 2014 Delmar, Cengage Learning Introduction As of January 1, 1993, any person repairing or servicing motor vehicle air conditioners must certify to the Environmental Protection Agency (EPA) that they have acquired and are properly using approved equipment. Each technician authorized to use such equipment must be properly trained and certified under Section 609 of the Clean Air Act.
Copyright © 2014 Delmar, Cengage Learning System Overview This chapter serves as a guide for technicians working in the air-conditioning and mobile-refrigeration trades. It outlines some of the safe handling and environmental concerns for working with todays refrigerants. You will also learn about the EPAs penalty for undocumented refrigerant gas usage as it relates to ozone depleting substances.
Copyright © 2014 Delmar, Cengage Learning CAUTION This chapter by no means exempts a technician from getting proper certification or licensing, as mandated by the EPA.
Copyright © 2014 Delmar, Cengage Learning Stratospheric Ozone Depletion The ozone layer is located in the stratosphere, high above the earths surface (Figure 2-1). The ozone layer is formed by ultraviolet (UV) light from the sun acting on oxygen molecules. The ozone layer is often referred to as a protective layer because it absorbs and scatters ultraviolet light from the sun, preventing some of the harmful ultraviolet light from reaching the earths surface.
Copyright © 2014 Delmar, Cengage Learning Stratospheric Ozone Depletion (continued) Figure 2-1. Location of the stratosphere, far above the earths surface.
Copyright © 2014 Delmar, Cengage Learning Stratospheric Ozone Depletion (continued) Chlorofluorocarbons (CFCs) gradually float up to the stratosphere, where the chlorine reacts with the ozone, causing it to change back into oxygen (Figure 2-2). When the ozone layer decomposes, more UV radiation penetrates to the earths surface (Figure 2-3). Stratospheric ozone depletion is a global concern, and it will take the cooperation of many nations to bring this process under control.
Copyright © 2014 Delmar, Cengage Learning Stratospheric Ozone Depletion (continued) Figure 2-2. CFC molecules gradually float up to the stratosphere where they damage the ozone layer.
Copyright © 2014 Delmar, Cengage Learning Stratospheric Ozone Depletion (continued) Figure 2-3. How chlorofluorocarbons (CFCs) destroy the ozone layer.
Copyright © 2014 Delmar, Cengage Learning Stratospheric Ozone Depletion (continued) The health and environmental concerns caused by the breakdown of the ozone layer include: Increase in skin cancers Suppression of the human immune response system Increase in cataracts Damage to crops Damage to aquatic organisms Increase in global warming
Copyright © 2014 Delmar, Cengage Learning The Montreal Protocol The Montreal Protocol is a response to the global nature of ozone depletion. On September 16, 1987, in Montreal, 24 nations and the European Economic Community (EEC) signed the Montreal Protocol on substances that deplete the ozone layer. Most of the nations that are major producers and consumers of CFCs and halon signed the agreement. On August 1, 1988, the EPA put this agreement into regulations for the United States (Figure 2-4).
Copyright © 2014 Delmar, Cengage Learning The Montreal Protocol (continued) Figure 2-4. The ozone depletion process.
Copyright © 2014 Delmar, Cengage Learning The Clean Air Act The Clean Air Act directs the EPA to establish regulations to prevent the release of ozone- depleting substances. Sections 608 and 609 deal with ozone depletion. Section 608 pertains to stationary air- conditioning equipment, mobile-refrigeration equipment, and air-conditioning equipment that uses R-22.
Copyright © 2014 Delmar, Cengage Learning The Clean Air Act (continued) Section 609 deals with the mobile motor vehicle open-driven air-conditioning industry. The sale of refrigerant containers weighing less than 20 pounds is restricted to technicians certified in Section 609 (Figure 2-5). Technicians working with HFC-134a mobile vehicle air conditioning must be trained and certified by an EPA-approved organization. Technicians already certified to handle CFC-12 are not required to recertify to work with HFC-134a.
Copyright © 2014 Delmar, Cengage Learning The Clean Air Act (continued) Figure 2-5. One-pound disposable refrigerant can.
Copyright © 2014 Delmar, Cengage Learning EPA Penalties EPA penalty policies are based on the U.S. Clean Air Act and its international counterparts. Noncompliance could result in fines of up to $25,000 a day, per violation. Refrigerant leaks not fixed within 30 days are subject to a $32,500 fine per day, per unit. Purchasing used or imported refrigerant gas calls for fines of $300,000 per 30-pound cylinder of refrigerant gas.
Copyright © 2014 Delmar, Cengage Learning Greenhouse Effect The greenhouse effect is a naturally- occurring process that helps to heat the earths surface and atmosphere. The earth absorbs incoming solar radiation and then cools by emitting long- wavelength infrared radiation. This radiation is absorbed by greenhouse gases, thereby preventing the heat from escaping.
Copyright © 2014 Delmar, Cengage Learning Greenhouse Effect (continued) The increase in greenhouse gases may increase average global temperature. In the last few centuries, human activity has directly or indirectly caused the concentration of the major greenhouse gases to increase. Scientists predict that the greenhouse effect will cause the planet to become warmer.
Copyright © 2014 Delmar, Cengage Learning Greenhouse Gases Some of the major greenhouse gases and their sources are: CO 2 burning of carbon-based fuels CH 4 anaerobic bacteria in rice fields, cows, and sewage N 2 O fossil fuels and fertilizer CFCs refrigeration and spray cans Methane (CH4) directly related to food production and population growth
Copyright © 2014 Delmar, Cengage Learning Greenhouse Gases (continued) Figure 2-6. The greenhouse effect.
Copyright © 2014 Delmar, Cengage Learning Refrigerants Most refrigerants in use today are compounds containing carbon, fluorine, usually chlorine, and sometimes hydrogen, bromine, or iodine. Refrigerants in vehicle air-conditioning systems may be referred to as CFCs, HCFCs, or HFCs. –CFC refrigerants contain chlorine, fluorine, and carbon. –HCFC refrigerants contain hydrogen, chlorine, fluorine, and carbon. –HFC refrigerants contain hydrogen, fluorine, and carbon.
Copyright © 2014 Delmar, Cengage Learning CFCs Because CFCs contain no hydrogen, they are chemically very stableeven if released into the atmosphere. CFCs contain chlorine, which is very damaging to the ozone layer. These two characteristics give CFC refrigerants a high ozone-depletion potential, or ODP. The manufacture of these refrigerants was discontinued as of January 1, 1996.
Copyright © 2014 Delmar, Cengage Learning HCFCs Hydrochlorofluorocarbons (HCFCs) refrigerants contain chlorine, which is damaging to the ozone layer. These refrigerants have a lower ozone-depletion potential (ODP). HCFC-22, or R-22, is used extensively in commercial air conditioning, transport refrigeration equipment, home air conditioners, refrigerators, freezers, and dehumidifiers. New equipment today will not work with R-22.
Copyright © 2014 Delmar, Cengage Learning HFCs Hydrofluorocarbon (HFC) refrigerants have largely replaced CFC-12 in the automotive field. These refrigerants contain no chlorine and have an ozone-depletion potential of zero. These refrigerants, however, are considered greenhouse gases. The refrigerant used in most automotive and truck trailer applications to replace CFC-12 is HFC-134a. The truck trailer industry also uses R404A.
Copyright © 2014 Delmar, Cengage Learning Alternative Refrigerants Considerations for any new refrigerant are chemical stability in the system, toxicity, flammability, thermal characteristics, efficiency, ease of detection in the event of leaks, environmental effects, compatibility with system materials, compatibility with lubricants, and cost. In general, HFC-134a has replaced R-12 in all truck/automotive applications. Recycling and recovery of refrigerants is still required, regardless of the new refrigerant.
Copyright © 2014 Delmar, Cengage Learning Alternative Refrigerants (continued) Changes to a system for the new refrigerant usually amount to replacement of incompatible seals and compressor lubricants. Lubricants typically used with CFC-12 do not mix with HFC-134a. Polyalkylene glycols (PAGs) mix properly with R- 134a at low temperatures, but have upper temperature problems and incompatibility with aluminum bearings and polyester hermetic motor insulation.
Copyright © 2014 Delmar, Cengage Learning Alternative Refrigerants (continued) Ester-based synthetic (POE) lubricants for HFC-134a resolve these problems, but are incompatible with existing PAG or mineral oils. POE oils are incompatible with as little as 1% residual oil (PAG or traditional mineral) in the system. In operation, HFC-134a is very similar to CFC-12.
Copyright © 2014 Delmar, Cengage Learning Disposable Refrigerant Cylinders Disposable refrigerant cylinders are commonly used in the automotive air-conditioning market. These cylinders are not refillable with refrigerant or any other product. Refrigerant cylinders are usually color-coded to identify the type of refrigerant they contain. The color code for containers filled with R-134a is light blue. Be sure to follow EPA regulations in your area for safe legal disposal of these cylinders.
Copyright © 2014 Delmar, Cengage Learning Disposable Refrigerant Cylinders (continued) Disposable cylinders are equipped with a safety relief valve to prevent over-pressurizing of the cylinder, which can happen if the cylinder is subject to excessive heat. Cylinders should be stored and transported in a dry environment to prevent rusting. The internal pressure of a cylinder containing 1 ounce of liquid refrigerant and one that is full is the same. If containers are left outdoors, they will eventually deteriorate and may explode.
Copyright © 2014 Delmar, Cengage Learning Disposable Refrigerant Cylinders (continued) Disposable refrigerant containers that are very rusty should have the contents removed and be properly discarded. Before disposing a cylinder, it must be completely emptied. This means that the cylinder should be put on a refrigerant recovery machine and the cylinders contents drawn into a vacuum. Follow EPA regulations for proper disposal of cylinders in your area (Figure 2-7).
Copyright © 2014 Delmar, Cengage Learning Disposable Refrigerant Cylinders (continued) Figure 2-7. Disposable refrigerant cylinders.
Copyright © 2014 Delmar, Cengage Learning Refillable Cylinders Refillable refrigerant cylinders are commonly used in the air-conditioning/refrigeration industry. These cylinders contain the same refrigerants that are also available in disposable cylinders. Refillable cylinders are regulated in their design, fabrication, and testing by DOT. Refillable cylinders may also be marked with a color to indicate which refrigerant they contain. This type of container may be used with refrigerant recycling equipment.
Copyright © 2014 Delmar, Cengage Learning Refillable Cylinders (continued) Cross contamination can become a problem if cylinders are interchanged, so the technician should clearly mark virgin, recycled (removed, filtered, and oil separated), or recovered (dirty) on the cylinder. Due to the rising cost of refrigerants, proper recycling and storage of the refrigerant for reuse in other equipment will save the shop owner money. Refillable cylinders contain a warning decal to caution the user against physical contact with or exposure to the refrigerant.
Copyright © 2014 Delmar, Cengage Learning Refillable Cylinders (continued) Refillable refrigerant containers must be retested at 5-year intervals because corrosion of the cylinder exterior or damage caused by mishandling cannot always be avoided. The valves of these tanks should be checked occasionally, especially the relief valve. Check that nothing is blocking the relief valve and that no visible deterioration or damage has occurred. If damage is visible, empty the cylinder and have the cylinder repaired (Figure 2-8).
Copyright © 2014 Delmar, Cengage Learning Refillable Cylinders (continued) Figure 2-8. Refillable refrigerant cylinder.
Copyright © 2014 Delmar, Cengage Learning CAUTION Never under any circumstance use a cylinder with a faulty pressure relief valve or a cylinder with an obvious structural problem.
Copyright © 2014 Delmar, Cengage Learning Cylinder Color Code Refrigerant cylinders may be color-coded to indicate the type of refrigerant they contain. Refrigerant 12 White Refrigerant 22 Green Refrigerant 134a Light Blue Refrigerant 502 Light Purple Refrigerant 401B Yellow/Brown Refrigerant 402A Light Brown Refrigerant 404A Orange
Copyright © 2014 Delmar, Cengage Learning Refrigerant Safety Any technician working in the air-conditioning field should understand general safety considerations concerning fluorocarbon refrigerants. Before coming into contact with any refrigerant, a technician should understand the safety concerns for the specific product. Long-term health effects are not yet known. Manufacturers can provide specific product information for the refrigerants they produce.
Copyright © 2014 Delmar, Cengage Learning Health Hazards Technicians working with fluorocarbon refrigerants should always wear safety goggles and non-leather work gloves. Shops where refrigerant work is done should be well ventilated to prevent technicians from inhaling large concentrations of refrigerants. Exposure time for some of the new refrigerants is lower than those of refrigerants with which technicians may already be familiar.
Copyright © 2014 Delmar, Cengage Learning CAUTION Refrigerant should NEVER come into contact with skin or eyes. Liquid refrigerant quickly evaporates when exposed to the air and will almost instantly freeze skin or eye tissue, so serious injury or blindness could result from contact with liquid refrigerant.
Copyright © 2014 Delmar, Cengage Learning First Aid A victim who has inhaled refrigerant should be removed to a place where the air is fresh. If the victim is not breathing, call 911 and administer artificial respiration at once. If the victim experiences labored breathing, oxygen should be administered. The victim should avoid all stimulants/depressants, such as caffeine, tobacco, and alcohol. Get the patient to a doctor for continued treatment.
Copyright © 2014 Delmar, Cengage Learning First Aid (continued) If a persons eyes come in contact with liquid refrigerant, the eyes should be flushed with water for a minimum of 15 minutes, and get the person to a doctor immediately. If skin comes in contact with liquid refrigerant, it should be flushed with warm water to warm the skin gradually (Figure 2- 9).
Copyright © 2014 Delmar, Cengage Learning First Aid (continued) Figure 2-9. Eye wash station.
Copyright © 2014 Delmar, Cengage Learning Poisonous Gas Most halogenated compounds decompose, producing toxic vapor when they come in contact with high temperatures. If the compound contains chlorine, hydrochloric acid is formed and a small amount of phosgene gas is formed if a source of water (or oxygen) is present. Halogen gases are easily identified by a very sharp/sour smell. When these odors occur, the area should be evacuated and opened up to allow fresh air to dissipate the gas.
Copyright © 2014 Delmar, Cengage Learning General Workplace Precautions Read all product labels and material safety data sheets (MSDS). Always work in a well-ventilated area. Never allow refrigerant vapors to come in contact with open flames, sparks, or hot surfaces. Do not weld or steam clean an air-conditioning system. When testing for leaks, do not mix R-134a with air.
Copyright © 2014 Delmar, Cengage Learning General Workplace Precautions (continued) Do not recover or transfer refrigerant into a disposable cylinder. Do not transport refrigerant in the passenger compartment of a vehicle. Never expose refrigerant to open flames, high temperatures, or direct sunlight. Wear safety goggles, non-leather gloves, and suitable work clothing when working with refrigerants. Ensure that showers and eye wash fountains of the deluge-type are readily accessible.
Copyright © 2014 Delmar, Cengage Learning Handling Refrigerant Cylinders Keep cylinders secured in an upright position. Store refrigerants out of direct sunlight in a clean, dry area. Refrigerant cylinders should not be permitted to attain temperatures above 125 F (51.6 C). Do not store refrigerant containers in a vehicle. Keep the outlet port of the refrigerant cylinder capped and the valve hood securely screwed onto the neck of the cylinder at all times when it is not being used.
Copyright © 2014 Delmar, Cengage Learning Handling Refrigerant Cylinders (continued) Never apply an external source of heat to a refrigerant cylinder. Never drop or strike a refrigerant cylinder with any object. Never lift a refrigerant cylinder by its valve or valve cover. Never try to repair the valve. Never tamper with the safety device. Avoid exposure to vapors through spills or leaks.
Copyright © 2014 Delmar, Cengage Learning Handling Refrigerant Cylinders (continued) Evacuate the area if a large refrigerant spill occurs. Check to ensure that the cylinder label matches the color code. Open cylinder valves slowly, and close after every use. Always ventilate the work area before using open flames. Avoid contact with liquid refrigerant because frostbite may occur.
Copyright © 2014 Delmar, Cengage Learning Handling Refrigerant Cylinders (continued) Do not attempt to refill disposable cylinders. Do not remove or alter cylinder identification markings. Be careful not to cut or gouge the cylinder. Keep cylinders away from corrosive materials and water. Dont use cylinders that are extensively rusted or otherwise deteriorated. Never leave an empty reusable cylinder with its valve open to the atmosphere.
Copyright © 2014 Delmar, Cengage Learning Summary Anyone repairing or servicing motor vehicle air conditioners must be certified by the EPA. The ozone layer is a protective layer in the atmosphere that absorbs and scatters ultraviolet light from the sun. With the ozone layer decomposing, more UV radiation penetrates to the Earths surface. The Clean Air Act directs the EPA to establish regulations to prevent the release of ozone- depleting substances.
Copyright © 2014 Delmar, Cengage Learning Summary (continued) The upsurge in greenhouse gases may increase average global temperature. Refrigerants referred to as CFCs contain chlorine, fluorine, and carbon. Refrigerants referred to as HCFCs contain hydrogen, chlorine, fluorine, and carbon. Refrigerants referred to as HFCs contain hydrogen, fluorine, and carbon. HFCs, such as R-134a, are not ozone-depleting but contribute to global warming.
Copyright © 2014 Delmar, Cengage Learning Summary (continued) Refillable refrigerant cylinders may be used with refrigerant recycling equipment. Refrigerant cylinders may be color-coded to indicate the type of refrigerant they contain. If a person has inhaled refrigerant, he or she should be moved to an area where there is fresh air. If the person is not breathing, call 911 and start artificial respiration. Poisonous gas may be formed when refrigerant comes into contact with a heat source.
Chapter 8 Refrigerant Management. 2 Objectives After completing the material in this chapter, the student should be able to: –List the desired properties.
Unit 9: Refrigerant and Oil Chemistry and Management – Recovery, Recycling, Reclaiming, and Retrofitting Section 2: Safety, Tools and Equipment, and Shop.
SECTION 4 ELECTRIC MOTORS UNIT 9 REFRIGERANT AND OIL CHEMISTRY AND MANAGEMENT – RECOVERY, RECYCLYING, RECLAIMING, AND RETROFITTING.
Automotive Heating and Air Conditioning CHAPTER Automotive Heating and Air Conditioning, 7e James D. Halderman | Tom Birch SEVENTH EDITION Copyright ©
CCNA1 v3 Module 9 v3 A+ CORE JEOPARDY K. Martin CCNA1 v3 Module 9 RouterModesWANEncapsulationWANServicesRouterBasicsRouterCommands RouterModesWANEncapsulationWANServicesRouterBasicsRouterCommands.
R22 Phase Out Presentation To inform our customers of the single most important changes to the air conditioning industry in modern.
Copyright Progressive Business Publications Blue Ridge Safety Association Safety Presentations Compressed Gasses.
Section 3.0 – The Spread of Harmful Substances. Potentially harmful substances are spread and concentrated in the environment in various ways.
1 Air Conditioning EPA Core. 2 Effects of Ozone Depletion Skin Cancer Cataracts Crop loss Immune system deficiencies. Skin Cancer Cataracts Crop loss.
RECOVERED and RECYCLED ODS Sh.Enkhamgalan (Ph.D) MUST. (HCFC) ХӨРГӨХ БОДИСЫН МЕНЕЖМЕНТИЙН ХӨТӨЛБӨРИЙГ МОНГОЛ УЛСАД ХЭРЭГЖИЛТИЙН ЭХЛЭЛИЙН УУЗАЛТЫН ХӨТӨЛБӨР.
WEL COME TO COE RAC SECTOR ITI UTTARSANDA. ADVANCE MODULE :-I Advance Module in Domestic, Commercial Refrigeration and Air Conditioning.
How can we be environmentally responsible citizens? Green house effect.
Ozone Depletion Reducing the manufacture and release of halogenated organic chemicals.
CFC/HCFC MANAGEMENT Training Conference 2013 – Chicago, IL 1.
Global Warming !. What is Global Warming ? Global warming is the increase in the average temperature of earth’s near-surface air and oceans. Global warming.
Compressed Gas Cylinder Safety. Industrial, manufacturing, repair shops, fabrication shops and construction operations require the use of compressed gases.
CFCs/HCFCs Warrington Williams – Thanks to John Meyer Environmental Affairs Director John Morrell & Company.
Plan ► What is ozone? ► Where is it found? ► What is its origin? ► Importance ► Ozone depletion ► Impacts ► Solutions: protecting the ozone layer.
Our Natural Protection Against UV light. The Ozone layer that blocks out the sun’s harmful rays is being depleted. Todd Olsen Professor Kimball Chem 1A.
The environment is all of our surroundings. This includes the atmosphere, oceans, soil and all living things.
Ozone & Greenhouse Effect. What is Ozone? Ozone is a molecule that occurs in the Stratosphere Ozone absorbs harmful UV rays from the sun O 3 + uv O 2.
POLLUTION MANAGEMENT 5.6 Depletion of stratospheric ozone.
Workplace Hazardous Materials Information System (WHMIS) Hazardous Household Product Symbols (HHPS) There are two systems of hazardous materials labeling.
Unit 4: General Safety Practices Section 2: Safety, Tools and Equipment, and Shop Practices.
The contamination of the earth’s atmosphere by harmful substances Numerous studies have linked it to a wide variety of health problems, including.
Ozone Depletion. OZONE DEPLETION IN THE STRATOSPHERE Less ozone in the stratosphere allows for more harmful UV radiation to reach the earth ’ s surface.
Ch. 8.2 Air Pollution and Solutions Essential Question: How Do People use Earth’s Resource? What Causes Outdoor and Indoor Air Pollution? What Causes damage.
Safety Training Presentation Flammable and Combustible Liquids.
Understanding & Tracking Antarctica’s Ozone Hole Based on material from ecohealth101.org & ozonewatch.gsfc.nasa.gov.
Climate Change Lesson 5 How humans effect greenhouse gas production SNC2P Nicole Klement.
Outline of Presentation What is the Ozone layer? What is the Ozone layer? How is ozone created and destroyed? How is ozone created and destroyed? What.
Section 2 Safety, Tools and Equipment, Shop Practices Unit 4 General Safety Practices.
Material Safety Data Sheet. The Material Safety Data Sheet provides the important information on every chemical you use this year. This information includes.
AIM: How does pollution affect the environment?. Water Pollution disposal of substances into water- lakes, rivers, oceans Sewage wastes from homes & factories.
Chapter 7 : Climate Interactions Lesson 6: Human Activity and Climate Change.
T HE T HIN B LUE B LANKET Environmental Science 2.1.
Tulane University - Office of Environmental Health & Safety (OEHS) COMPRESSED GAS CYLINDERS FOR EMPLOYEES WHO HANDLE, TRANSPORT, STORE OR USE COMPRESSED.
1 Refrigerants and refrigerant oil. 2 The clean air act of 1990 The Environmental Protection Agency [EPA] enforces regulations set in place by the clean.
Training Charts Chemical Handling and Safety. CORROSIVE COMPOUNDS ACIDS / ALKALIS - CAN CAUSE IRRITATION AND/OR BURNING OF THE SKIN AND OTHER BODY TISSUES.
THE OZONE LAYER. In atmosphere there are natural concentrations of greenhouse gases. Short wavelength rays and the visible light of the sun can cross.
Compressed Gases. © Business & Legal Reports, Inc Session Objectives You will be able to: Identify compressed gases by the labels Safely transport,
Global Changes in the Atmosphere Pages What is global warming? The gradual increase in the temperature of Earth’s atmosphere Over the last 120.
East Carolina University Compressed Gas Safety Training Program Presented by the Office of Environmental Health and Safety.
Green house Effect Simulation. Announcements Quiz Tomorrow on Atmosphere LTs 1-3 Homework tonight – Finish Atmosphere Quiz Review.
It’s not just about Global Warming… The Problem with the Ozone Layer.
The Greenhouse Effect. Greenhouse Effect Radiation from the sun easily penetrates the layer of gases surrounding the Earth (the atmosphere) Some of this.
1 The Greenhouse Effect Natural and Anthropogenic.
Safe Chemical Handling. Categories of Hazardous Chemicals Corrosive Flammable Toxic Reactive Biological (infectious) Carcinogen (cancer-causing) Radioactive.
© 2017 SlidePlayer.com Inc. All rights reserved.